6.5mm STW

[Africanut]

Any other members out there shooting 6.5 mm STW --I have one built on a 700 action 28 inch Kreiger with 8.5 twist- Rifle is absolutely uncanny accurate with 100gr ballistic tips (.19" 3 shot groups). @ a little over 4000fps--Problem is when I switched over to 139 vld moly Bergers with 3 or 4 different powder combos - can't get them to shooter better than about 3/4 moa.. I have my rifle doped on the 100 gr. Ballistic tips , but they will not exit whitetails past the 400 yd mark.. If anybody else has some loads to share, I will reciprocate in kind....GOOD LUCK AND GOOD SHOOTING.....

 

[Chopaka81]

I can not help you with specific data. My brother shoots a 7mm STW AI, Nosler 140gr BT at 3500 fps. It shoots into the .3's. He is using either H1000 or RL-25. not sure which one. He has messed around with IMR-7828 too.

I would think that you will find that you will get your best results with the ultra-slow burning powders. There are 3 loads listed for the 6.5 STW on www.reloadersnest.com all of which use very slow burning powders. I also see that they have an extensive list of loads for the 257 STW. I would leverage off them as starters and go from there.

Get a accurate micrometer and a good cronograph. We stop when we see 0.001" of case head expansion, and then back off 1.0 to 1.5 grs of powder and call that maximum when loading for a wildcat. I like to use those New Hodgon Extreme powders, they tend to be more stable over temperature.

Proceed very carefully and pay very close attention to what your cronograph and micrometer are telling you. It might be smart to invest in a bullet puller too. That way if you go to hot, you can pull the bullets, dump the powder and back off.

Good Luck!